Fire alarm device



Nov. 3, 1936. J. GRISON FIRE ALARM DEVICE Original Filed Jan. 2, 1934 2 Sheets-Sheet 1 I v INVENTOR c/OSEPH G/e/sa/V "BY 2 a ATTORNEY NOV. 3, 1936. J G RISQN Re. 20,158

FIRE ALARM DEVICE Original Filed Jan. 2, 1934 2 Sheets-Sheet 2 'IIIIIIIIII/lllllll llIIIIIIIIIIIIIIIIIIIIIIIIIIIIII INVENTOR c/OSEPH 6R/50N Ci Gama,

ATTORNEY Reissued Nov. 3, 1936 UNITED STATES PATENT OFFICE FIRE ALARM DEVICE tion of Delaware Original No. 1,987,590,

dated January 8, 1935,

Serial No. 704,885, January 2, 1934. Application for reissue March 4, 1936, Serial No. 67,187

8 Claims.

This invention relates to fire detector and alarm devices, and more particularly to improvements in self-contained devices which produce an audible signal when certain parts thereof attain a predetermined temperature.

Heretofore, there have been produced fire detector and alarm devices provided with thermostatic or similar temperature responsive means to close an electric circuit when a predetermined temperature is reached, the closing of the electric circuit causing the energization of a solenoid to ring a bell or the like. Such devices, however, have been found objectionable in that they are essentially dependent upon a source of electrical energy; and in many instances the very fire which the device is intended to detect may destroy the electrical wiring and disconnect the source of electrical energy so that the fire alarm device becomes ineffective to produce an alarming signal as desired. In other words, such devices are not reliable; and reliability is very important in fire alarm devices.

It is, therefore, an object of this invention to provide a self-contained fire detector and alarm device, which does not rely in any way upon an external source of energy, said device being provided with heat movable or temperature responsive means to cause the device to produce an alarming signal when a predetermined temperature is attained.

A' further object is the provision of a fire detector and alarm device of simple structure, having the parts thereof constructed and arranged so that there is no likelihood of the device getting out of order, and enabling the device to be readily and conveniently manufactured and marketed at a low cost. 7

These and other objects are attained by the novel construction, combination and arrangement of parts hereinafter described and shown in the accompanying drawings, constituting a material part of this disclosure, and in which:

Fig. 1 is an elevational view of the device, with a part broken away to show internal details thereof.

Fig. 2 is a sectional view of the device.

Fig. 3 is a sectional view taken on line 33 of Fig. 2.

Fig. 4 is a plan view of a temperature responsive device used in the fire alarm device.

Fig. 5 is a. sectional view showing the arrangement of the temperature responsive device in connection with detent means used in the fire alarm device.

Fig. 6 is an elevational view of a fire alarm device having a modified form of temperature responsive means.

Fig. 7 is a sectional view taken on the line 1-1 of Fig. 6, looking in the direction of the arrows and showing the heat movable or temperature responsive and detent means used in the modified form.

Referring to Fig. l, the fire detector and alarm device is shown to include a bell III of the gong type, which produces an audible signal by impact with the curved tip I I of a plunger or clapper I2, slidable in guides I3 and pivotally connected to a pitman I4, the latter being pivotally and eccentrically connected to a crank wheel I5, which is fixed to and rotates with a shaft I6 supported by a plate 20, which is between the plates I1 and I8, and connected to plates I1 and I8 by posts I9.

Positioned between plates I1 and 20 is a coiled flat spring 2 I, of the clock type, having one end 22 attached to a post I9, the other end of the spring being attached to the shaft 23, to which is fixed a ratchet wheel 24 engaging a pawl 25 carried by a large gear 21 which pawl is urged into position to engage the ratchet wheel by means of a spring 26 (see Fig. 3).

Loosely mounted on the shaft 23 is the large gear 21, meshing with a pinion 28 fixed to a shaft.

30. On the shaft 3|] is also fixed a gear 29, engaging a pinion 3| on a shaft 33, which has fixed thereto a gear 32, engaging pinion 34 which is fixed to shaft 5| and the pinion 34 engages the gear 52, fixed to shaft I6, to which the crank wheel I5 is attached. The spring may be wound by a key 35 of the conventional type in the well known manner.

When the spring 2| is being wound, the ratchet 24 and shaft 23 are rotated counter-clockwise as viewed in Fig. 3, the large gear 21 remaining stationary and the pawl 25 overriding the teeth of the ratch 24. The spring is prevented from unwinding by means of the pin 26. When, however, the pin 36 is released the shaft 23 and the ratchet 24 are rotated clockwise as viewed in Fig. 3. The teeth of the ratchet 24 engage the pawl 25 which is secured to the gear 21 so that the gear 21 is likewise rotated clockwise as viewed in Fig. 3; the gear 29 is rotated counter-clockwise; the gear 32, clockwise; the gear 34, anti-clockwise; and the gear 52 and shaft I6, clockwise. Inasmuch as the crank wheel I5 is secured to the shaft I6 the crank wheel I5 is rotated, which imparts a reciprocating movement to the plunger I 2. It is of no great importance as to which shaft carries the crank wheel I5, it being well understood in the art that the more reduction gearing which is employed,

the path of pin 36 by a compression spring 40..

The rod 33 is held down, against the action of spring 40, by a strip of metal 42 which is fusible at a predetermined temperature. The strip of fusible metal 42 is positioned in a frame 43 and bears against a brace 4|, which directly engages the rod 33. The frame 43 is attached to a plate 44, which engages the threaded portion 46 of the member 39.

In operation, when a predetermined temperature is caused by a fire or otherwise, .fim..metal' strip 42 fuses and allows the rod 38 to release the plunger l2. 'Unwinding of spring 2| will cause rotation of the crank wheel IE .to reciprocate rapidly the plunger l2, so that the curved end Ii thereof will strike the gong I0 and produce an alarming sound, which will continue for an appreciable length of time. The device may be placed in condition to again give an alarm when a predetermined temperature is reached by providing the device with a new fusible strip 42.

In Figs. 6 and 7 are shown details of a modified form of detent for preventing movement of the plunger i2. In this form, the pin 36 is normally engaged by a fiat strip 46 of thermostatic metal lying in a plane parallel to the plane in which the plunger moves. By thermostatic strip, 1, of course, mean a strip composed of two sheets of metal having different expansion coefllcients, the said two sheets lying parallel and being united together. A change of temperature, therefore, causes one of the sheets to expand more than the other, which causes the free end of the sheets to move transversely of the plane of the sheets, that is, causes the thermostatic strip to move when heated from the position shown in full lines in Fig. '7 to the position shown in dotted lines in the said figure. The strip 46 extends at right angles to the path of movement of the pin 36 and is attached to a post 41 by means of a knurled nut 43. The bell or gong III is secured to the tubular member 39 by means of a similar knurled nut 49.

In certain of the claims I refer to a heat movable device and by this expression I mean any device which is moved by a change in temperature, such as the strip of bi-metal material 46 shown in the drawings. The expression heat movable device is used in contra-distinction to a device which has a fusible element therein which when melted would release certain mechanism which might perform certain functions.

In operation, when the thermostatic strip 46 is heated to a predetermined temperature, it will curl outwardly as shown in dotted lines in Fig. 7, to release the pin .36 to allow free reciprocation of the plunger II, as above explained. Among the advantages of having a heat movable device might be mentioned the following: a

1. It eliminates a fusible element which would have to be replaced entailing (a) The expense of the new fusible element.

(b) When a fusible element is used the instrument is rendered useless after it has been used until the new fusible element is obtained and installed, whereas with the thermostatic strip it'is always ready for use.

(a) The trouble to install the new fusible element, which might require the services of an expert.

(d) The danger and possibility of the fusible element being damaged and made inoperative for purpose intended because it projects out beyond body of mechanism and is exposed to tampering or accidental derangement or deatruction.

2. The heat movable device is cheaper in the first instance.

3. The heat movable device is far simpler in structure.

4. The heat movable device is easier to manufacture.

. 5. The heat movable device would not deterioratelas quickly as a fusible element.

6. The heat movable device eliminates any needless parts.

'7. The heat movable device is simple and reliable.

8. The heat movable device is protected by the body of the mechanism and is not exposed to tampering or accidental derangement or destruction.

Attached to wall I1 is a tab 50 having an aperture to enable the device to be conveniently himg on a wall.

From the above description, it will be seen that I have provided a simple and effective self-contained fire detector and alarm device which will automatically produce an audible signal when a predetermined temperature has been attained; and which is not dependent upon outside sources of energy, such as an electric current, for its operation.

The foregoing disclosure is to be regarded as descriptive and illustrative only, and not as restrictive or limitative of the invention, of which obviously an embodiment may be constructed including modifications without departing from the general scope herein indicated and denoted in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a fire alarm device, a bell, a plunger, means to guide the plunger in a straight line, spring means to reciprocate the plunger into and out of contact with the bell, and fusible means to prevent movement of the plunger until a predetermined temperature has been reached.

2. In a fire alarm device, a bell, a plunger, a revolution crank connected to the plunger, spring means to cause the crank to be rotated through a number of revolutions to cause the plunger to reciprocate longitudinally of its length into and out of contact with the bell, a pin projecting from the plunger, and a strip of heat movable metal mounted adjacent the plunger and engaging the pin to prevent movement of the plunger until a predetermined temperature has been reached.

3. In a fire alarm device, a bell, a plunger, means to reciprocate the plunger longitudinally of its length into and out of contact with the bell, a pin on the plunger, and a strip of heat movable metal mounted adjacent the plunger and engaging the pin to prevent movement of the plunger until a predetermined temperature has been reached.

4. In a fire alarm device, a hell, 9. vringing means movable longitudinally of its length for said bell, a. guide for said ringing means, a heat movable device, and means carried by the ringing means and normally engaging the heat movable device.

5. In a fire alarm device, a bell, a ringing means for said bell, a heat movable device consisting of a flat bi-metallic strip, a holding means carried by the ringing means, said strip having an edge thereof normally engaging said holding means and holding inoperative said ringing means, said heat movable device being so constructed as to curl laterally of its length to release said holding means when a predetermined temperature has been reached.

6. In a fire alarm device, a bell, a clapper therefor, means to move said clapper back and forth repeatedly longitudinally of its length, a heat movable device normally preventing the operation of said clapper but being so constructed as to curl outwardly to curl laterally of its length to release the clapper when a predetermined temperature has been reached, and means to operate said clapper when it is released.

7. In a fire alarm device, a bell, a clapper therefor, a heat movable device, a stop carried by said clapper and normally engagingsaid heat movable device, said heat movable device being movable laterally out of engagement with said stop so as to release the clapper when a predetermined temperature has been reached, and means to operate repeatedly said clapper longitudinally of its length when it is released.

8. In a fire alarm device, a revolution member, means whereby said member is rotated, a bell, a striker operatively connected near one of its ends to said member and having its striking end at the other end thereof so that said striker is reciprocated longitudinally of its length, and a heat movable means controlling said striker, said heat movable means being so designed as when heated to a predetermined degree will cause the release of said striker.

JOSEPH GRISON. 

